Phillygenin inhibits the tumorigenicity of hepatocellular carcinoma cell by interfering with the TCA cycle metabolism pathway

hillygenin (PLE) is a lignan component extracted from the Forsythiae Fructus, has been reported to show the effects of liver protection,anti-inflammatory and anti-oxidant, and anti-tumor effects.This study aimed to investigate PLE's anti-hepatocellular carcinoma (HCC) properties and explore the possible molecular mechanisms. Hep3B and HCCLM3 cells were selected to evaluate the anti-tumor effects of PLE in vitro.RNA-sequence (RNA-seq) was used to identify possible molecular targets and pathways. LC-MS was used to evaluate the effect of PLE treatment on the primary metabolites of HCCLM3 cells.Tumor xenograft was performed in nude mice to examine the anti-tumor properties of PLE in vivo. The results showed that PLE resulted in an inhibition on the tumorigenicity of HCC cells, including inhibiting the proliferation and migration and also induce apoptosis of cells in vitro.RNA-seq following PLE treatment identified 4949 differentially expressed genes (DEGs), which were highly enriched in ell cycle pathway and apoptosis pathway. In addition, metabolomics analysis revealed that PLE interfered with the TCA cycle metabolism pathway of HCC cells by significantly inhibiting the synthesis of citrate metabolites. Furthermore, subcutaneous tumor formation experiments revealed that PLE significantly suppressed the tumor growth. Immunohistochemical analysis further revealed that treatment of PLE significantly decreased the expression of the proliferation marker Ki67. Our findings demonstrated that PLE has significant anti-tumor effects and has the potential to be a candidate anti-cancer drug for the treatment of HCC.